Ramallah - A top aide of Palestinian President Mahmoud Abbas accused Hamas Thursday of "obstructing" efforts to reconcile the warring Palestinian political factions, by raising "new conditions."

Yasser Abed Rabbo said Abbas' secular Fatah movement was willing to form a national unity government with Hamas.

But the radical Islamist movement was raising new conditions because it was not interested in reconciliation and was instead working to consolidate its hold over the Gaza Strip, he said.

He accused Hamas of killing, arresting and torturing Fatah fighters in Gaza.

"Hamas has turned its guns from the enemy (Israel) to Fatah after the withdrawal of the occupiers" from Gaza, he said, charging that Hamas had turned hospitals and mosques into detention and interrogation centres for Fatah members after Israel has destroyed all the security buildings in the strip during its 22-day offensive.

The two rival Palestinian factions have been locked in a bitter power struggle since Hamas defeated Fatah in January 2006 democratic parliamentary elections, one year after the moderate Abbas was elected in separate presidential elections on a contrasting platform.

The struggle culminated in Hamas violently seizing sole control of the Gaza Strip in June 2007. Abbas' four-year term as president has ended January 9, but he has vowed to stay in office until new presidential and parliamentary elections can be held simultaneously.

According to Fatah officials, Hamas has killed 19 Fatah members and shot 16 others in the leg during, and in the aftermath of, Israel's Gaza offensive, which ended Sunday with each side making a unilateral ceasefire.

Abed Rabbo, also the secretary general of the Fatah-dominated Palestine Liberation Organization (PLO), said Ramallah-based caretaker Prime Minister Salam Fayyad had informed Abbas in a letter that "the future of his government and its continuation is in the hands of Abu Mazen (Abbas) when he sees an opportunity to form a national reconciliation government."

This letter "is proof that we want to have reconciliation and have one national authority that includes everyone," Abed Rabbo told a news conference in Ramallah.

"We heard from (Damascus-based Hamas leader Khaled) Meshaal about new conditions for reconciliation," he said, charging these had no other purpose "than to obstruct and prevent reconciliation."

"Hamas' enemy now is not Israel. It is Fatah and the PLO because it considers them more dangerous to its separatist regime," he said.

He accused Hamas of working toward total separation of Gaza from the West Bank, calling this a "conspiracy" which was being encouraged by Israel, supported by Iran and aided by other Arab groups.

"We will not allow this conspiracy to happen, no matter what the cost," he vowed. A Fatah and PLO delegation would travel to Cairo Sunday to discuss the Egyptian-mediated truce in Gaza, he added. (dpa)